I've only driven the Nissan GT-R GT3, Ford Focus RS RX and the Ford Mustang RTR GT4 so far, but on default setups they're pretty good out of the box. You'll just need to adapt your driving skills and habits to each vehicle if you choose to use only the default setups.

Have mainly been driving GT3 cars so far and playing on PC I definitely prefer loading the SMS stable setup over the loose it defaults to (atleast it does with a wheel) but beside that I dont have any complaints about defaults for the cars I have tried so far.
I'm sure they can be improved upon if you know your way around a car but for us that dont I think they do a good job